The present invention is concerned with the provision of a composite container which constitutes a viable alternate to the conventional metal can now finding particular use in the beverage industry for non-carbonated or lightly carbonated soft drinks.
The beverage industry has converted almost entirely to necked metal cans which enable the use of smaller diameter end covers on the can bodies; for example, the use of a 209 (2 and 9/16 inch) cover on a 211 (2 and 11/16 inch) metal can body. Such an arrangement provides both certain economies and particular advantages. The use of the smaller size cover is obviously less expensive. The inward necking of the body prior to the application of the cover enables the formation of a flush-sided container which is more easily and compactly packaged, reduces chime damage, facilitates the application of plastic six-pack retainers, etc.
In proposing the use of composite can bodies as an alternative to the conventional aluminum or other types of metallic can bodies, it is essential that the necked configuration be maintained in order to retain the particular advantages associated therewith, including the use of smaller, less expensive, covers and the ability to provide flush-sided containers, while at the same time acquiring the particular advantages of a composite can body including decreased costs, increased insulation, and, in some instances, increased strength.
In attempting to arrive at a satisfactory composite body substitute for the conventional metal or aluminum body, it was proposed initially that the end portion of the composite body be pre-necked, as is the procedure with the metal bodies. However, not only is this a time consuming step, but also it has been found difficult to achieve a proper and consistent necking of the bodies, due to the nature of the composite material. In addition, the pre-necking of composite tubular bodies appears to have an undesirable effect on the structural integrity of the composite body. Such a pre-necking of a composite can body will be noted in FIGS. 8 through 12 of U.S. Pat. No. 2,343,550 to Grove, and is also suggested in FIG. 12 of U.S. Pat. No. 2,641,827 to Carpenter. Carpenter, at FIG. 11, illustrates a flush-sided construction wherein the rolled portion of the cover flange and engaged portion of the body wall are crushed against the disc-backed collar portion 27 snugly received within the upper end portion of the body prior to a formation of the seam. Such a crushing of the seam, including the engaged portion of the composite container, will do substantial damage to the integrity of the juncture of body and cover.